I am excited by the introduction of 32-bit Arduino Due. But on second thoughts, what are the applications that are suitable for 32-bit Arduino that the 8-bit Arduino cannot do? As the 32-bit version is more expensive than the 8-bit ones, there must be good reason for using it.

For control purposes, 8-bit MCUs are good enough. Is Arduino Due good for signal processing apps? Or is it stuck in some no-man's land? Too fast for this, too slow for that??

I googled "applications for arduino due" but I do not see much applications turning up.

Well, you can think of using the Due for anything where the Uno does not have enough program space, data space, or pins. You could have used an 8-bit Arduino MEGA instead, but the MEGA is more expensive than the Due...Here's a little table: Cost IOS Flash Ram SpeedUno $30 19 32k 2k 16MHzMEGA $60 70 256k 8k 16MHzDue $50 70 512k 96k 84Mhz

The Due may also have a full-sized 64/80bit floating point type, which could be handy for some people.And a real D-A converter.

Since it's CHEAPER than the closest equiv 8-bit system, the real question is "are there any applications that are unsuitable for a 32bit arduino?" (one that pops up pretty quick is "things requiring 5V IO.)

Well, you can think of using the Due for anything where the Uno does not have enough program space, data space, or pins. You could have used an 8-bit Arduino MEGA instead, but the MEGA is more expensive than the Due...Here's a little table: Cost IOS Flash Ram SpeedUno $30 19 32k 2k 16MHzMEGA $60 70 256k 8k 16MHzDue $50 70 512k 96k 84Mhz

The Due may also have a full-sized 64/80bit floating point type, which could be handy for some people.And a real D-A converter.

Since it's CHEAPER than the closest equiv 8-bit system, the real question is "are there any applications that are unsuitable for a 32bit arduino?" (one that pops up pretty quick is "things requiring 5V IO.)

I haven't been keeping up with Due progress much. Are there any commercial shields available yet that are 3.3volt only or able to switch I/O voltages based on the new IOref pin?

Well, you can think of using the Due for anything where the Uno does not have enough program space, data space, or pins. You could have used an 8-bit Arduino MEGA instead, but the MEGA is more expensive than the Due...Here's a little table: Cost IOS Flash Ram SpeedUno $30 19 32k 2k 16MHzMEGA $60 70 256k 8k 16MHzDue $50 70 512k 96k 84Mhz

The Due may also have a full-sized 64/80bit floating point type, which could be handy for some people.And a real D-A converter.

Since it's CHEAPER than the closest equiv 8-bit system, the real question is "are there any applications that are unsuitable for a 32bit arduino?" (one that pops up pretty quick is "things requiring 5V IO.)

Wow! The pricing of Atmega2560 is ridiculous. The Due will kill off 2560. However, there is still one area which Atmega2560 wins Due despite its higher price. It is lower power consumption. Running at higher clock speed, the Due has to suffer higher power consumption compared to its 8-bit counterpart. So, for battery-operated applications, Atmega2560 is still worth considering.

Running at higher clock speed, the Due has to suffer higher power consumption compared to its 8-bit counterpart.

That's somewhat questionable. Smaller transistors, lower voltage, etc. And that's before you get to the "it runs faster, so you can spend more time in low-power shutdown modes", or "The clock is all PLL controlled, so if it's using too much power because it's running too fast, just run slower!"

Board-wise, none of the Arduino boards are designed for extra-low power consumption anyway.

The way I see it, 8-bit CPUs are likely to continue to be sensible as long as you don't bump into the limitations of 8bit architectures. The AVR is designed around 16bit addresses, so as long as your program is less than 64k words, and your data is less than 64k bytes, it'll probably continue to be viable (architecturally, anyway. Whether it will be overly expensive because it was designed with older design rule and uses a bigger chunk of silicon, is a separate question.) When you get to something like the 2560 or the big xmegas, and have to start worrying about near and far pointers and such, it's time to start wondering whether it would all work out better on an architecture with 32bit addresses...

I strongly believe that a 32-bit Arduino Due Is capable of controlling a spaceship visiting the moon and guide it back to Earth afterwards if programmed very well.

Looks like the processor that was on the Apollo mission was 16 bit, had 4K of RAM, 72K ROM, and ran at 2MHz. So twice the word size, RAM, and ROM, but 1/8th the speed of an uno. I'd say an uno could make it to the moon and back.